Designs for various bicycle pedals exist which allow a cleat which is attached to the bottom of a shoe to be engaged by the pedal. This allows the motion of the shoe moving up and down to be translated to the pedal while keeping the shoe and pedal in contact. One common design utilizes two cleat retaining members. One of the cleat retaining members for cleat attachment is fixed and immovable. The other cleat retaining member is movable. A bias is applied to the movable cleat member so that some force is required to move it sufficiently to allow the engagement or disengagement of a cleat. Such designs generally employ a helical spring member to apply a bias to the movable cleat retaining member. Alternative designs have resulted in pedals having an eccentric camming unit which connects to a stud projecting from the bicycle rider's shoe, or a piece of the cleat extends into an recessed area in the pedal surface and is affixed to the pedal by means of the bias force created by a circular spring wire. In another alternative the pedal has a centrally located mushroom or T-shaped extension which protrudes from the surface of the pedal and engages a shoe cleat by means of a spring wire.
Although the above-described pedal designs are an improvement over pedals requiring clips or toe cages, a certain amount of care is required in positioning the cleat for proper engagement with the pedal, and the amount of force required for engagement is relatively high. In addition, most of the currently available cleat-engaging pedals are relatively bulky and heavy, necessitating the use of more energy by the rider to propel the bicycle forward. Furthermore, the solid filled-in structure of the current designs allows mud and other debris to build up between the cleat and the pedal, making engagement of the cleat more difficult and clogging the cleat engagement mechanism. A need exists for a simple, lightweight clipless pedal that allows the rider to easily and securely engage a shoe cleat with the pedal without it also becoming too readily disengaged and resists clogging. The present invention addresses this need.